The titration of an acid (H2A) with LiOH solution generates the following titration curve. What are the main components (more than half of the initial amount of H2A, besides H2O) at equivalence point 1 (EP1) and equivalence point 2 (EP2)?

Main Components at EP1 Main Components at EP2
A H2A and OH− A2− and OH−
B HA− and Li+ A2− and Li+
C HA− and OH− HA− and Li+
D H2A and Li+ HA− and OH−

Which of the following pairs of elements belong to the same groupa. h and he b. li and bec. c and pb d. ga and ge

Astudent is given a sample of a blue copper sulfate hydrate. he weighs the sample in a dry covered porcelain crucible and got a mass of 23.875 g for the crucible, lid, and sample. the mass of the empty crucible and lid was found earlier to be 22.652 g. he then heats the crucible to expel the water of hydration, keeping the crucible at red heat for 10 minutes with the lid slightly ajar. on colling, he finds the mass of crucible, lid, and contents to be 23.403 g. the sample was changed in the process to very light clue anhydrous cuso4. if there are again 100.0 g of hydrate, how many grams of cuso4 are in it? how many moles of cuso4? (hint: molar mass of cuso4 = 159.6 g / mole. what per cent of the hydrate is cuso4? you may convert the mass of cuso4 to moles.)

If blood contains 150g of hemoglobin per liter of blood, how much hemoglobin would be contained in 10 ml of blood